The effects of triclosan, 2,4-D, and their by-products on the adrenocortical cells of rainbow trout

Abstract:

The ubiquitous presence of anthropogenic chemicals and their transformation products in surface water represents a toxicological concern from both an ecological standpoint and a human perspective as many of these chemicals are capable of altering hormonal function. Endocrine disrupting compounds can be traced back to numerous sources and may fall under the class of pesticide, industrial chemical, pharmaceutical, personal care product, and/or heavy metals. The adrenal gland is the most common target for endocrine disruptors, although in comparison to the sex steroids, this system has received much less attention in published research. Corticosteroids play a pivotal role in many physiological processes, including immunity, cognitive function, growth, metabolism, reproduction, mineral balance, and blood pressure. A primary cell culture of rainbow trout adrenocortical cells was used to investigate the endocrine disrupting activity of two commonly detected water-borne toxicants, a personal care product, triclosan (TCS), a pesticide, dichlorophenoxyacetic acid (2,4-D), and their transformation products, methyl-triclosan (M-TCS) and dichlorophenol (DCP). Previously, it has been shown that TCS, 2,4-D, and DCP exhibit a potential for endocrine disruption, although it is currently unknown if these chemicals are capable of affecting corticosteroid balance. In this study, all four chemicals showed significant inhibitory effects on corticosteroid synthesis, even though there were considerable differences in their activity. The chemical that exhibited the highest toxicity was 2,4-D, followed by TCS, DCP, and M-TCS. Both parent-compounds proved to be more toxic than their degradation products. More research with suitable test systems is needed to determine the mechanism(s) of action of these corticosteroid disruptors and the health risk that they may present.